Various long length commercial vehicles, such as tractor-trailer combinations, buses, trucks, recreational vehicles, and the like, present potentially hazardous situations to persons following behind these vehicles. Because of the dimensions of the commercial vehicle, it is common for long length commercial vehicles to swing wide in rounding a corner.
While various devices are currently utilized to assist in warning trailing vehicles of the movements of a commercial vehicle, such apparatus are typically ineffective or confusing. For example, some semi-trailers utilize turn signal lights located on the underside of the trailer in a central location. However, these lights are only noticeable when the following vehicle is in the truck operator's blind spot, immediately adjacent the trailer. Thus, the following vehicle is located for a potential collision upon movement of the tractor-trailer into the signaled turn.
Most large commercial vehicles must utilize a rapid sequence of brake applications when downshifting. These brake applications can easily be mistaken for hazard flashers to a following vehicle.
Another method for warning following vehicles of potentially hazardous situations, includes the use of printed signs on the back of the commercial vehicle. Such signs are limited in effectiveness for several reasons. First, the signs are frequently placed above the normal line of sight for automobile drivers, and therefore are not easily noticed. In addition, the signs can include diagrams which are difficult to understand, and which are easily covered with dirt and road grime, making them difficult to read.
Because buses tend to make sudden and frequent stops, it is difficult for following vehicles to determine whether the bus is braking, or whether the bus is utilizing hazard flashers.